Presentation 4 Numerical Modeling T. Weaver 1

Purpose of Numerical Modeling Predict E* given aggregate and binder properties Predict pavement performance and assess influence of multiple variables (loads, environment) on behavior Comparative assessment of mix designs 2

Numerical Methods Discrete Element 3

Numerical Methods Finite Elements 4

Constitutive Models Hooke’s Law 5

Constitutive Models Viscoelasticity Viscoplasticity 6

Constitutive Models Viscoelastoplastic Parameter Anisotropy,  Viscoelastic stiffness, E 1 Viscoelastic stiffness, E 2 Poisson’s ratio, Drucker-Prager friction angle,  Drucker-Prager cohesion,  0 Perzyna’s viscoplastic parameter,  Perzyna’s viscoplastic parameter, N Dilation Parameter,  Damage Parameter,  1 Damage Parameter,  1 Damage Parameter,  1 Hardening Parameter,  1 Hardening Parameter,  2 7

Analyses using Viscoplasticity 8

Analyses with Viscoelastoplastic Model 9

Work Plan Validate proper use of viscoplastic model using ABAQUS Utilize E* test results to determine model parameters for viscoplastic model Develop empirical relation between asphalt pavement properties and viscoplastic model parameters 10

Finite Element Analyses 11

Future Work Develop specialized FEA code for predicting E* 12